Adapter for non-rotary tool elements used with a rotary-hammer device



June 1961 0.0. AMUNDSEN ETAL ADAPTER FOR NON-ROTARY TOOL ELEMENTS USED WITH A ROTARY-HAMMER DEVICE Filed June 1, 1960 Unite The present invention is directed to an adapter for use with a rotary-hammer device and, more particularly, to an adapter which is readily attachable to the nose of a rotary-hammer device whereby to prevent rotation of a tool element mounted in the device and adapted for reciprocal hammering action only.

It is an important object of the invention to provide a new and improved adapter for use with a rotary-hammer device whereby to prevent rotation of tool elements, such as chisels, mounted in the device for reciprocal hammering action only.

Another important object of the invention is to provide a new and improved adapter of the character described which is releasably attachable to the nose end of a rotary-hammer device by resilient means and which is slidably engageable with the shank portion of a tool element mounted in the rotary-hammer device in a manner permitting reciprocal hammering actuation thereof while preventing rotation thereof.

Further objects of the invention are to provide a new and improved adapter of the character described which may be easily and economically mass produced by means of conventional machine tools, which is rugged, and which may be easily mounted on the nose end of a rotary-hammer device and removed therefrom.

Certain other objects of the invention will, in part, be obvious, and will in part appear hereinafter.

For a more complete understanding of the nature and scope of the invention reference may now be had to the accompanying drawings wherein:

FIG. 1 is a side elevational view, partially in vertical section, of a rotary-hammer device having a one-piece cold chisel mounted therein for reciprocal hammer-like actuation only;

FIG. 2 is a vertical section taken generally on the line 22 of FIG. 1;

FIG. 3 is a top plan view of the spring retainer of FIG.

FIG. 4 is a front end view of the spring retainer;

FIG. 5 is a front end view of an adapter embodying the invention;

FIG. 6 is a vertical section taken generally on the line 6-6 of FIG. 5; and

FIG. 7 is a vertical section taken through the nose portion of the rotary-hammer device of FIG. 1 with the adapter of FIGS. 5 and 6 mounted thereon and showing the adapter in engagement with the cold-chisel whereby to prevent rotation thereof during reciprocal hammerlike actuation thereof.

As illustrated in FIG. 1, a rotary-hammer device 10 comprises a multi-part housing including a tubular portion 11, a first-handgrip 12, and a second gripping han dle 13 which projects normally from one side of the device 10. The rotary-hammer device 10 further includes an electric motor (not shown) which is adapted to be connected to a power source through a power cord 14. The electric drive motor circuit includes an on-and-oif switch which is controlled by a trigger-like member 15 associated with the handgrip 12.

The rotary-hammer device 10 includes a cylinder 17 which is rotatably mounted within the tubular housing portion 11 and is operably connected through a suitable gear train to the electric motor whereby during actuation Patented June 27, 1961 and of the motor the cylinder 17 is rotated within the housing portion 11. As shown in FIG. 1, the forward end of the cylinder 17 is rotatably mounted in the forward end of the housing portion 11 by a suitable bearing 18. An axially bored drive member 19 having an internal hexagonal formation is threadedly secured in the forward end of the cylinder 17 for rotation therewith and a smooth bored non-rotatable nose member 20 is secured to the forward end of the tubular housing portion 11. An annular groove 22 is formed on the outer circumference of the nose member 20 adjacent the front end thereof. The front end surface of the nose member 20 is provided with a pair of diametrically opposite longitudinally extending bores 23. The purpose for the groove 22 and the bores 23 will be evident hereinafter.

Tool elements which are mounted in the device 10 for reciprocal hammer-like actuation thereby are provided with long shank portions which project through the drive member 19 and into the cylinder 17 for impact engagement by a striker member 26 which is pneumatically reciprocated within the rotary cylinder 17. The striker member 26 is pneumatically reciprocated in the cylinder 17 as a result of reciprocation in the rear end of the cylinder 17 of a power piston (not shown) which is operably connected in a well-known manner to the electric motor. Suitable porting is provided in the cylinder 17 for the pneumatic actuation of the striker member 26. Rotaryhammer devices of this type are fully disclosed in copending applications, Serial No. 18,550, filed March 30, 1960, and Serial No. 19,784, filed April 4, 1960.

Tool elements which are mounted in the rotary-hammer device 10 for rotary actuation thereby have shank portions provided with external hexagonal formations adapted for rotary driving engagement with the internal hexagonal formation of the drive member 19 whereby such tool elements are operably connected for rotation with the cylinder 17. Thus, a long shank tool element having an external hexagonal formation for slidable interengagement with the internal hexagonal formation of the drive member 19 may be provided with a combined rotary-hammering action due to the simultaneous rotation of the cylinder 17 and the reciprocal actuation therein of the striker member 26.

Tool elements which are mounted in the rotary-hammer device 10 for non-rotary reciprocal hammer actuation thereby are provided with rounded shank portions extending through the drive member 19 whereby such tool elements are not drivingly connected through the drive member 19 to the cylinder 17 for rotation therewith. Such a tool element, in the form of a cold-chisel 30, is illustrated in FIGS. 1 and 7. The one-piece cold chisel 30 is characterized by a body portion 31, a chisel formation 32 formed on one end thereof, and an integral shank portion including a rounded portion 33 which extends through the drive member 19 and into the cylinder 17 for impact engagement by the striker member 26. A portion of the shank of the cold-chisel 30 is enlarged and is provided with an external hexagonal formation 35 for a purpose which will be evident hereinafter.

Forwardly of the enlarged hexagonally shaped portion 35, the cold-chisel 30 is provided with a reduced-in-diameter portion defining an annular groove 36 which is adapted to receive a tool element retainer member 37 which is pivotally mounted on the nose member 20 of the rotaryhammer device 10. As best illustrated in FIGS. 1, 3 and 4, the tool element retainer member 37, which is of a heattreated steel wire construction, is characterized by a pair of spaced arms 38 having inwardly bent end portions 39 which are pivotally mounted in a pair of diametrically opposite radially extending bores 40 formed in the nose member 20. As shown in the drawings, the radially extending bores 40 may be formed in the base of the annul-ar groove 22 and angularly located midway between the longitudinally extending bores 23 formed in the front end surface of the nose member 20. The opposite ends of the arms 38 are interconnected by a loop portion 41 which is adapted to be pivoted into embracing engagement in the annular groove 36 whereby to retain the cold-chisel 30 in the rotary-hammer device during hammer-like reciprocation thereof.

It has been found, during hammer-like reciprocation of a non-rotatable tool element, such as the cold-chisel 30, that there will be an undesirable tendency for the coldchisel 30 to rotate somewhat even though it is not drivingly connected to the rotating cylinder 17 through the drive member 19. The invention, therefore, is primarily concerned with the development of means readily attachable to the rotary-hammer device 10 for preventing rotation of non-rotary tool elements, such as the cold-chisel 30.

An adapter 45 embodying the invention is illustrated in FIGS. 5, 6, and 7. The adapter 45 includes a generally flat circular plate or disc member 46 having a diameter substantially equal to the diameter of the front end of the nose member 20. The disc member 46 is provided on each of its faces with centrally located, axially bored hublike projections 47 and 48. The hub-like projection 48 is adapted to be inserted into the bore of the nose member 20 whereby it serves to position the adapter 45 relative to the nose member 20 with the bore of the disc member 46 in axial alignment with the rotary axis of the rotary-hammer device 10. Two pins 49 are mounted in the disc member 46 in diametrically opposite relationship to each other with such pins being provided with projecting end portions adapted to be received in the longitudinally extending bores 23 formed in the front end surface of the nose member 20 whereby the pins 49 aid in positioning the adapter 45 relative to the nose member 20. An important function of the pins 49 is to prevent rotation of the adapter 45 relative to the nose member 20. The bore of the disc member 46 is provided with an internal hexagonal formation 52 adapted for slidable interengagement with the external hexagonal formation 35 on the coldchisel 30 whereby to permit reciprocal hammer-like action of the cold-chisel 30 while preventing rotation thereof. With the hub-like projection 48 fitted in the bore of the nose member 20, the nose assembly of the rotary-hammer device 10 is strengthened whereby inadvertent use of the chisel 80 as a lever for a prying action will not be detrimental to the device 10.

The adapter 45 is readily attached to and removed from the nose member 20 by means of a pair of specially formed fiat spring members 54 which are adapted for resiliently mounting the adapter 45 on the nose member forwardly from the bight portion 57,, is provided with a finger engageable end portion 58 which is adapted, when urged toward the adapter 45, to release the bight portion 57 from its latching engagement in the annular groove 22 by exerting a lever-like action thereon.

'In operation, the adapter 45 is merely snapped onto the nose member 20 with the hub-like projection 48 inserted in the central bore of the nose member 20 and the pins 49 inserted in the bores 23 in the nose member 20. Manipulation of the free end portions 58 of the two spring members 54 in the manner described serves to release the adapter 45 fromits latching engagement with the nose member 20 whereby to readily permit removal thereof, as when it is desirable to insert a tool element adapted for rotary or combined rotary-hammering actuation in the rotary-hammer device 1'0.

It will be understood that certain changes may be made in the construction or arrangement of the adapter disclosed herein without departing from the spirit and scope of the invention as defined in the appended claims.

We claim:

1. An adapter for attachment to the nose of a rotaryhammcr device for preventing rotation of a tool element mounted in thedevice for hammer-like actuation only, said adapter comprising, a generally flat disc member adapted to be attached to the nose of the rotary-hammer device, means on said disc member for releasably attaching the same to the nose of the device, and means on said disc member for engagement with a tool element mounted in the device whereby to prevent rotation of the tool element during hammer-like actuation thereof.

2. An adapter for attachment to the nose of a rotaryhammer device for preventing rotation of a tool element mounted in the device for hammer-like actuation only, said adapter comprising, an axially bored generally flat disc member adapted to be attached to the nose of the rotary-hammer device, interengaging means on said disc member and on the nose of the device for positioning the disc member relative to the nose of the device with the bore of the disc member axially aligned with the rotary axis of the device, resilient means carried on said disc member for releasably attaching the disc member to the nose of the device, and means on said disc member for non-rotatable slidable interengagement with a tool element mounted in the device whereby to prevent rotation of the tool element during hammer-like actuation thereof.

3. An adapter for attachment to the nose of a rotaryhammer device for preventhlg rotation of a tool element mounted in the device for hammer-like actuation only, said adapter comprising, an axially bored generally flat disc member adapted to be attached to the nose of the rotary-hammer device, interfitting pin-and-recess means as sociated with said disc member and the nose end of the device for positioning the disc member relative thereto with the bore of the disc member axially aligned with the rotary axis of the device, resilient means carried on said disc member for releasably attaching the disc member to the nose of the device, and an internal formation in said axial bore of said disc member adapted for slidable interengagement with a similarly shaped external formation on a tool element mounted in the device whereby to prevent rotation of the tool element during hammenlike actuation thereof.

4. An adapter for attachment to the nose of a rotaryhammer device for preventing rotation of a tool element mounted in the device for hammer-like reciprocation only, said adapter comprising, a generally fiat disc member having an axial bore extending therethrough and adapted to be disposed against the nose of the rotary-hammer device, a pair of pins extending through said disc member and adapted to be received in a pair of longitudinally extending bores formed in the outer end of the nose of the device whereby the bore of said disc member is axially aligned with the rotary axis of the device, flat spring means carried on said disc member and adapted for latching engagement in an annular groove formed in the outer circumference of the nose of the device whereby to releasably attach the disc member to the nose of the device, and means on said disc member for non-rotatable slidable engagement with a tool element mounted in the device whereby to prevent rotation of the tool element during hammer-like reciprocation thereof.

5. An adapter for attachment to the nose of a rotaryhammer device for preventing rotation of a tool element mounted in the device for hammer-like reciprocation only, said adapter comprising, a generally fiat disc member having an axial bore extending therethrough and adapted to be disposed against the nose of the rotary-hammer device, interengaging means on said disc member and on the nose of the device for positioning the disc member relative to the nose of the device with the bore of the disc member axially aligned with the rotary axis of the device, a pair of flat spring members carried on said disc member and having rearwardly disposed and inwardly sprung loop portions adapted for latching engagement in an annular groove formed in the outer circumference of the nose of the device whereby to releasably attach the disc member to the nose of the device, and an internal hexagonal formation in said axial bore of said disc member for slidable interengagement with an external hexag+ onal formation on a tool element mounted in the device whereby to prevent rotation of the tool element during hammer-like reciprocation thereof.

6. An adapter for attachment to the nose of a rotaryhammer device for preventing rotation of a tool element mounted in the device for hammer-like reciprocation only, said adapter comprising, a generally fiat disc member having an axial bore extending therethrough and adapted to be disposed against the nose of the rotary-hammer device, a pair of diametrically opposite pins extending through said disc member and adapted to be received in a pair of longitudinally extending diametrically opposite bores formed in the nose of the device whereby the bore of said disc member is axially aligned with the rotary axis of the device, a pair of flat spring members carried on said disc member and having rearwardly disposed and inwardly sprung loop portions adapted for latching engagement in an annular groove formed in the outer circumference of the nose of the device whereby to releasably attach the disc member to the nose of the device, each of said spring members having a manually manipulable free end portion for releasing said inwardly sprung loop portion from its latching engagement in the annular groove, and an internal hexagonal formation in said axial bore of said disc member for slidable interengagement with an external hexagonal formation on a tool element mounted in the device whereby to prevent rotation of the tool element during hammer-like reciprocation thereof.

7. For use with a rotary-hammer device having a cylinder rotatable in a housing, an axially bored drive member secured in the outer end of the cylinder, a striker member reciprocal in the rotatable cylinder for imparting a hammer-like action to tool elements mounted in the device and having shank portions projecting through the drive member into the cylinder, power means for simultaneously rotating the cylinder and actuating the striker member, and a non-rotatable collar-like nose member secured to the outer end of the housing, an adapter readily attachable to the rotary-hammer device for preventing rotation of rounded shank tool elements mounted in the device for reciprocal, hammer-like actuation only, said adapter comprising, a generally fiat plate member adapted to be mounted on the nose member, means on said plate member for releasably mounting said plate member on the nose member, and means on said plate member for engagement with a tool element mounted in the device whereby to prevent rotation of the tool element during hammer-like reciprocation thereof.

8. For use with a rotary-hammer device having a cylinder rotatable in a housing, an axially bored drive member secured in the outer end of the cylinder, a striker member reciprocal in the rotatable cylinder for imparting a hammer-like action to tool elements mounted in the device and having shank portions projecting through the drive member into the cylinder, power means for simultaneously rotating the cylinder and actuating the striker member, and a non-rotatable collar-like nose member secured to the outer end of the housing, the improvement comprising, an adapter readily attachable to the rotaryhammer device for preventing rotation of rounded shank tool elements mounted in the device for reciprocal, hammer-like actuation only, said adapter comprising an axially bored generally flat plate member adapted to be mounted on the nose member, interengaging means on said plate member and on the nose member-for positioning said plate member relative to the nose member with the bore of the plate member in axial alignment with the rotary axis of the rotary-hammer device, resilient means carried on said plate member for releasably mounting said plate member on the nose member, and means on said Plate member for slidable, non-rotatable engagement witha tool element mounted in the device whereby to prevent/rotation of the tool element during hammer-like reciprocation thereof.

9. For use with a rotary-hammer device having a cylinder rotatable in a housing, an axially bored drive member secured in the outer end of the cylinder, a striker member reciprocal in the rotatable cylinder for imparting a hammer-like action to tool elements mounted in the device and having shank portions projecting through the drive member into the cylinder, power means for simultaneously rotating the cylinder and actuating the striker member, and a non-rotatable collar-like nose member secured to the outer end of the housing, the improvement comprising, an adapter readily attachable to the rotaryhammer device for preventing rotation of rounded shank tool elements mounted in the device for reciprocal, hammer-like actuation only, said adapter comprising, an axially bored generally flat plate member adapted to be mounted on the nose member, inter-fitting pin-and-recess means associated with said plate member and with the nose member for positioning said plate member relative to the nose member with the bore of said plate member axially aligned with the rotary axis of the rotary-hammer device, resilient means carried on said plate member for releasably mounting said plate member on the nose memher, and an internal formation in said axial bore of said plate member adapted for slidable, non-rotatable engagement with a similarly shaped external formation on the shank of a tool element mounted in the device whereby to prevent rotation of the tool element during hammerlike reciprocation thereof.

10. For use with a rotary-hammer device having a cylinder rotatable in a housing, an axially bored drive member secured in the outer end of the cylinder, a striker member reciprocal in the rotatable cylinder for imparting a hammer-like action to tool elements mounted in the device and having shank portions projecting through the drive member into the cylinder, power means for simultaneously rotating the cylinder and actuating the striker member, and a non-rotatable collarlike nose member secured to the outer end of the housing and having an annular groove formed on the outer circumference thereof and a pair of longitudinally extending bores formed in the outer end surface thereof, the improvement comprising, an adapter readily attachable to the rotary-hammer device for preventing rotation of rounded shank tool elements mounted in the device for reciprocal, hammer-like actuation only, said adapter comprising, a generally flat plate member having an axial bore extending therethrough and adapted to be disposed against the outer end surface of the nose member, a pair of pins extending through said plate member and adapted to be received in the pair of bores formed in the outer end surface of the nose member whereby the bore of said plate member is axially aligned with the rotary axis of the rotary-hammer device, flat spring means carried on said plate member and adapted for latching engagement in the annular groove formed on the outer circumference of the nose member, and means on said plate member adapted for slidable, non-rotatable engagement with a tool element mounted in the device whereby to prevent rotation of the tool element during hammer-like reciprocation thereof.

11. An adapter for attachment to the nose of a rotaryhammer device for preventing rotation of a tool element mounted in the device for hammer-like act-nation only, said adapter comprising, an axially bored generally flat disc member adapted to be disposed against the nose of the rotary-hammer device, a rearwardly extending hub-like projection on said disc member adapted to be received in a central bore in thefnose'of the device whereby to position said disc member relative to the nose of the device with the bore of the disc member axially aligned with the rotary axis of the device, interengaging means on said disc member and on the nose of the device for preventing rotation of said disc member, resilient means carried on said disc memberfor releasably attaching said disc member: to the nose of the device, and means in the aXialbore of said disc member for non-rotatable slidable interengagement with a tool element mounted in the device whereby to prevent rotation of the tool element during hammer-like actuation thereof.

12. An adapter for attachment to the nose of a rotaryhammer device for preventing rotation of a tool element mounted in the device for hammer-like reciprocation only, said adapter comprising, a disc member having a centrally located hub-like projection on each face and an axial bore extending therethrough, said disc member being adapted to be disposed against the nose of the rotary-hammer device with one of said hub-like projections fitted in a central tool-element-receiving bore in the nose of the device whereby to axially align the bore of said disc member with the rotary axis of the device, a pair of diametrically opposite pins extending through the outer edge of said disc member and adapted to be received in a pair of longitudinally extending diametrically opposite bores formed in the nose of the device whereby to prevent rotation of said disc member relative to the nose of the device, a pair of flat spring mem- 'bers carried on said disc member and having rearwardly disposed and inwardly sprung loop portions adapted for latching engagement in an annular groove formed on the outer circumference of the nose of the device whereby to releasably attach the disc member to the nose of the device, and an internal formation in said axial bore of said disc member adapted for slidable interengagement with a similarly shaped external formation on a tool element mounted in the device whereby to prevent rotation of the tool element during hammer-like actuation thereof.

Gilman July 7, 1914 Saula Aug. 30, 1927 

